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我正在嘗試發送兩個帖子請求。兩者都應該同時發送（在我下面的當前代碼中，也許它會一個接一個地發送），並且應該等待最多80毫秒的響應，如果沒有響應請求，則將響應視爲空。同時發送2個帖子請求，等待最大響應80ms
public void SendRequests(String requestString){
TimeLimiter limiter1 = new SimpleTimeLimiter();
Response response1 = null;
System.out.println("Request Sent to 1");
try{
response1 = limiter1.callWithTimeout(new Callable<Response>() {
public Response call() {
//assume sendPost1 method will send POST request to some server and return response from server
return sendPost1(requestString);
}
}, 80, TimeUnit.MILLISECONDS, true);
}catch(Exception te){
te.printStackTrace();
}
TimeLimiter limiter2 = new SimpleTimeLimiter();
Response response2 = null;
System.out.println("Request Sent to 2");
try{
response2 = limiter2.callWithTimeout(new Callable<Response>() {
public Response call() {
//assume sendPost2 method will send POST request to some server and return response from server
return sendPost2(requestString);
}
}, 80, TimeUnit.MILLISECONDS, true);
}catch(Exception te){
te.printStackTrace();
}
//Do some process using response1 and response2
}
}
我要尋找一些方法來在同一時間發送2個POST請求，並等待80毫秒的響應，如果沒有響應，則考慮響應爲空。
@Gray 我按照下面的方法嘗試了您的解決方案。首先幾分鐘，我的servlet響應時間是2ms-10ms，但之後突然增加到200-300ms。
@WebServlet("/incomingTraffic")
public class ServletClass extends HttpServlet {
Gson gson;
private static URL url1;
private static URL url2;
public Exchanger() {
super();
}
public void init(ServletConfig config) throws ServletException {
gson = new Gson();
try{
url1 = new URL(Constants.URL1);
url2 = new URL(Constants.URL2);
}catch(Exception e){
}
}
public void destroy() {
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.getWriter().append("Served at: ").append(request.getContextPath());
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
ServletInputStream inputStream = request.getInputStream();
Reader reader = new InputStreamReader(inputStream);
//Request class is POJO
final Request requestString = gson.fromJson(reader, Request.class);
reader.close();
//long start = System.currentTimeMillis();
TimeLimiter limiter = new SimpleTimeLimiter();
//Response class is POJO
Response response1 = null;
Response response2 = null;
final ExecutorService threadPool = Executors.newCachedThreadPool();
Future<Response> future1 = threadPool.submit(new Callable<Response>() {
public Response call() {
return sendPost1(requestString);
}
});
Future<Response> future2 = null;
if(Some Condition Satisfy){
future2 = threadPool.submit(new Callable<Response>() {
public Response call() {
return sendPost2(requestString);
}
});
}
threadPool.shutdown();
long start = System.currentTimeMillis();
try {
response1 = future1.get(80, TimeUnit.MILLISECONDS);
} catch (ExecutionException ee) {
// job threw exception
} catch (InterruptedException ie) {
// this (main?) thread was interrupted, good pattern to re-interupt
Thread.currentThread().interrupt();
} catch (TimeoutException te) {
// wait timed out, maybe this is right?
response1 = null;
// try to interrupt the thread
future1.cancel(true);
}
if(requestString.getImp().get(0).getVideo() != null){
// wait for 80 MILLISECONDS minus how long we've been waiting for 2nd request
long end = System.currentTimeMillis();
//System.out.println(start+" - "+end);
long wait = 80 + start - end;
if (wait < 0) {
wait = 0;
}
try {
response2 = future2.get(wait, TimeUnit.MILLISECONDS);
} catch (ExecutionException ee) {
// job threw exception
} catch (InterruptedException ie) {
// this (main?) thread was interrupted, good pattern to re-interrupt
Thread.currentThread().interrupt();
} catch (TimeoutException te) {
// wait timed out, maybe this is right?
response2 = null;
// try to interrupt the thread
future2.cancel(true);
}
}
try {
threadPool.awaitTermination(80, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
}
if(response1 == null && response2 == null){
response.setStatus(HttpServletResponse.SC_NO_CONTENT);
}else {
response.setContentType("application/json");
PrintWriter output = response.getWriter();
response.setStatus(HttpServletResponse.SC_OK);
if(Some Condition){
response.getWriter().write(gson.toJson(response1));
}
else{
response.getWriter().write(gson.toJson(response1));
}
}
output.flush();
output.close();
}
}
protected Response sendPost2(Request request){
Response response = null;
String str = gson.toJson(request);
HttpURLConnection conn = null;
try{
conn= (HttpURLConnection) url2.openConnection();
conn.setDoOutput(true);
conn.setInstanceFollowRedirects(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Connection", "keep-alive");
conn.setRequestProperty("Content-Length", Integer.toString(str.length()));
DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
wr.writeBytes(str);
wr.flush();
wr.close();
int responseCode = conn.getResponseCode();
if(responseCode != 200){
return null;
}
Reader reader = new InputStreamReader(conn.getInputStream());
response = gson.fromJson(reader, Response.class);
conn.disconnect();
}catch(Exception e){
e.printStackTrace();
conn.disconnect();
}
return response;
}
protected Response sendPost1(Request request){
Response response = null;
String str = gson.toJson(request);
HttpURLConnection conn = null;
try{
conn= (HttpURLConnection) url1.openConnection();
conn.setDoOutput(true);
conn.setInstanceFollowRedirects(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Connection", "keep-alive");
conn.setRequestProperty("Content-Length", Integer.toString(str.length()));
DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
wr.writeBytes(str);
wr.flush();
wr.close();
int responseCode = conn.getResponseCode();
if(responseCode != 200){
return null;
}
Reader reader = new InputStreamReader(conn.getInputStream());
response = gson.fromJson(reader, Response.class);
conn.disconnect();
}catch(Exception e){
e.printStackTrace();
conn.disconnect();
}
return response;
}
}
考慮使用'ExecutorService';特別是'ExecutorService.invokeAll'。這應該做你需要的。 –
鏈接的問題有一些相關的答案。把這個問題作爲重複來解決。 –